Illustrators and animators have no shortage of inspiration from the best animated movies. But the history of animation is full of examples of promising projects that never saw the light of day despite hours of work going into sketches, visual development and character design.

A free online book now seeks to rescue these abandoned projects from oblivion, showcasing the art of some of the most intriguing cancelled animated films. From DreamWorks’ Me and My Shadow to Satoshi Kon’s ‘Dreaming Machine and Disney’s Joe Jump, it’s a wonderful resource that could provide animators with more sources of inspiration for their own work (also see our guide to the best 2D animation software).